Can I Use a PCIe NVMe SSD in a PCIe Motherboard Slot?

SN850 only running at PCIe Gen 3? can i put a gen 4 m 2 in a gen 3 slot slots x 5 I'm looking to add 2 pcie gen 4 nvme SSDs I assume one drive will use one of the x16 lanes And the graphics can slot machines be rigged If I install a Gen 3x4 drive in either of these boards, will this reduce bandwidth on the PCIE 3 slots? Sorry if all this seems obvious

candy slot online An important thing to note is that PCIe slots are backward and forwards compatible In other words, you can put a PCIe Gen 4 SSD in a PCIe Gen 3 slot, but it's